The writers of the famous cartoon had strict rules they needed to follow for this iconic rivalry. See the rules here.

One of the staples of the "Looney Tunes" was the constant battle between the Road Runner and Wile E. Coyote. The coyote would never seem to catch the Road Runner. (Probably why the coyote was always so skinny.)

My brothers and I would watch and whenever the coyote fell off a cliff, we would try to put our finger on the spot where he would land and the smoke cloud would appear. It turns out the writers had quite the guidelines they had to follow to make the cartoon.